The siren on my alarm sys (some off brand alarm, it works thats all that matters) took a crap recently. Don't really need a fancy alarm system since I don't have power windows/locks/trunk release, just needed the basics out of an alarm system. No use paying for extra features that I will never have installed, right?

I have a few relays and sockets lying around and was wondering if I could use one to run that to the stock horn?

Here's what I'm thinking should happen:

Pin 85 -- Ground for relay
Pin 86 -- + output for siren
Pin 87 -- to + wire on horn (green I believe)
Pin 30 -- not sure

Question is where to wire pin 30? Some other ground point? Or is this so far completely backwards?

The other part is this, I'm not sure if the siren output is constant or pulsed. I'll have to check that after work tomorrow. If it is pulsed, I know a relay should work. If it is constant, I can use the other parking light output as that is pulsed (for some reason it came with 2 of them <shrugs> )

Thanks in advance






Edited 1 time(s). Last edited Thursday, July 27, 2006 12:01 AM

OK, the siren output is steady, not pulsed. You can do a few things with this.

In that relay, a 12V constant would go to pole 30.

If you wanted to, you could connect a flasher in series, causing the horn to *honk* *honk*, ect ect between pole 87 and the horn.

Or, if you alarm has a horn honk wire (Viper does, it is a brown w/ black or white stripe---can't remember---some other companies do too) you can hook that up to 85 and then put power to 86 to complete the relay.

Sam


Ban low-performance cars, not high-performance ones.

Thanks Sam

Ok, so, here's what I know so far

The siren output is constant, whether the alarm is active or disabled. On a normal "chirp", the voltage drops for a split second.

While the siren is supposed to be active, the voltage is dropped to 6v, then back to 12v at the end of the cycle. I'm going to reset it (disconnect power) and see if that makes a difference (cutting power at the end of the alarm cycle)

The extra parking light wire is internally relayed. It clicks on an off and on again in a cycle of 1.5 seconds (on for .75, off for .75). I'm assuming that it is done this way so the incandecents have time to flash on and off. But too long to use for the horn cycle

I'm probably just going to end up getting a new alarm anyway.... there's a couple other minor irritations that I found today that leads me to believe the control box is screwed. When the door is open, the parking lights flash for 15 seconds.

For now, I'll just forego the siren/horn thing. I got the good parking space at work for the time being that is right in my line of sight @ my desk.

i would just use the parking light output to trigger a relay to honk your horn when the siren output is triggered.


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